anonymous

4 years ago

solve each system by substitution: -x-y-3z=-9, z=-3x-1, x=5y-z+23

well your second equation gives you the value of z
substitute z into the other two equations
now you have two equations to solve
so you would then make y the subject using one of the two equations you have
then substitute y into the other equation
then you will get a value of x
then substitute your value of x into the equation to get y
then substitute x and y into original equations to get z